The Subnautica 2 necrotic cyst that so many players search for is called the Necrolei Cyst in the game, and the official wiki lists it in exactly one biome: the Necrolei Hills, a shallow area (0 to 100 m) north-west of the Lifepod in the Coral Gardens. Hit the pink buds on top of a cyst with the Survival Multitool to collect Necrolei Buds, come back when they regrow, and turn every two buds into one Strong Acid at a Fabricator.
This guide reflects the official Subnautica 2 Wiki and the Unknown Worlds patch notes as checked on October 17, 2026, when the latest patch was Buddy System Hotfix 2 (October 6, 2026). Subnautica 2 is in Early Access, so locations, recipes and growth times can still change in later updates.
01
Necrolei Cyst at a glance
| Question | Answer from the official wiki |
|---|---|
| In-game name | Necrolei Cyst, the polyp stage of the Necrolei jelly |
| Where it grows | Necrolei Hills, Coral Gardens region, north-west of the Lifepod |
| Depth | The Necrolei Hills are listed at 0 to 100 m; no depth is given for single cysts |
| Tool | Survival Multitool |
| Drops | Necrolei Bud |
| Regrows | Yes, after a while; no timer is listed for wild cysts |
| Plantable | Yes, in a Growbed, placed with the Habitat Builder for 1 Necrolei Bud |
| Growbed output | 1 Necrolei Bud every 8 minutes |
| Main use | Strong Acid, made from 2 Necrolei Buds at the Fabricator |
If you typed necrotic cyst subnautica 2 into a search bar, this is the organism you were after. The mix-up is easy to make because the adult creature is called the Necrolei, but the wiki, its recipes and its databank entry all use the Necrolei Cyst name, so that is the name to look for among the Habitat Builder's plantables and in recipes. The databank for the Subnautica 2 Necrolei Cyst calls its buds a convenient, renewable source of strong acid, and the hills sit in your starting region.
02
Where to find Necrolei Cyst in Subnautica 2
The Necrolei Hills belong to the Coral Gardens, the starting region where your Lifepod splashes down. The wiki places the biome north-west of the Lifepod, and Hills Wreck 1 on its southern edge is listed about 275 m north-north-west of the pod, so the hills are close to where you begin. Wild cysts and buds are only listed in this biome, and the Necrolei Bud page calls the buds very abundant there.
The Necrolei databank gives the best search tip in one line: "Search in and around necrolei stalks." The wiki lists the cyst among the open-biome resources rather than the cave resources, and it has no map layer of individual cyst positions yet. Use the big stalks and these landmarks to orient yourself:
| Landmark | Position (per the wiki) | Depth | Coordinates listed on the official wiki |
|---|---|---|---|
| Necrolei Hills (biome) | North-west of the Lifepod | 0 to 100 m | -352633, 399931, -1886 |
| Hills Wreck 1 | Southern edge, 150 m north of the Heat Tolerance Angel Comb | 20 m | -351000, 410410 |
| Hills-Plateaus Wreck 1 | Border with the Plateaus, 220 m north-east of that Angel Comb | 45 m | -340050, 407600 |
| Hills-Plateaus Wreck 2 | Border with the Plateaus, 105 m west of Camp One | 30 m | -335315, 410753 |
The two Hills-Plateaus wrecks mark where the hills meet the Plateaus biome. Hills Wreck 1 and Hills-Plateaus Wreck 1 have entrances blocked by Bloom Biofilm, which the wiki says needs a Sonic Resonator, but they only serve as landmarks here. At the far edge, the seabed ends in a drop-off that the wiki describes as the current world border. For the wider layout of the Coral Gardens and every biome's depth range, see the map and biomes guide.
03
How to recognize a Necrolei Cyst
A cyst is a round green orb balanced on six long, thin legs, with small pink blisters scattered over the top. The harvestable Necrolei Bud sits on top of it and looks like a flower bud: a bright pink core with pink stems carrying tiny blue, petal-like bits. The wiki's gallery also shows the cysts' bioluminescence at night.
The adult Necrolei is the bigger landmark: a very large anchored jelly shaped like an upside-down trumpet, with deep blue ridges and soft pink arms around its rim that glow in the dark, and older ones stack up to about six of these tiers. Its databank describes the cyst as the stage an old, injured or starving Necrolei reverts to, and the cysts then bud off clones that drift away to find food.
04
How to harvest Necrolei Buds
Equip the Survival Multitool, which the Fabricator makes from 3 Titanium and is available from the start of the game, and strike the buds on top of a cyst. The cyst itself stays in place and its buds regrow after a while, so the same patch is worth revisiting. The wiki does not list a regrowth timer for wild cysts or a fixed number of buds per harvest.
Two scanning notes help here. The Buddy System update (Early Access 1.2, August 19, 2026) made sources of acid appear as green dots in the Scanner HUD. The wiki also marks the cyst and its bud as Bioscannable; together they count as one entry toward the Bioscanner's bio scan total, which unlocks extra passive Biomod slots once it is high enough. Scanning a cyst adds its databank entry as well.
05
Plant Necrolei Cysts in a Growbed
You do not have to swim back to the hills for every batch. The Buddy System patch notes include the line "Necrolei Cysts can now be planted in Growbeds," and the wiki's Habitat Builder lists the Necrolei Cyst as a plantable that costs 1 Necrolei Bud. Here is what the wiki says about the Growbed itself:
- Blueprint: scan two Growbed fragments (locations below).
- Recipe: 1 Titanium with the Habitat Builder.
- Placement: inside or outside a seabase, directly on the ground or on the roof of a Room, and you can extend it into larger shapes.
- Yield: a planted cyst grows 1 Necrolei Bud in 8 minutes; harvest it, then wait for the next one.
| Growbed fragment (per the wiki) | Coordinates listed on the official wiki |
|---|---|
| On the roof of the Research Outpost | -209506, 425607 @ 135m |
| Behind the Research Outpost | -210792, 427075 @ 140m |
| On a cliff near the Karakorum Metal Farms | -148946, 404033 @ 370m |
The Research Outpost is a pioneer seabase at 140 m on the edge of the Overgrown Ruins, far deeper than the hills themselves. Going by the listed numbers, one planted cyst supplies enough buds for one Strong Acid every 16 minutes, so a few planted cysts add up quickly. The wiki does not say whether a cyst grows in an interior bed; the Growbed databank only advises matching each plantable to its preferred environment, seawater or open air.
06
What Necrolei Buds are used for
The main job of the buds is Strong Acid: the Fabricator turns 2 Necrolei Buds into 1 Strong Acid. That blueprint unlocks together with the Power Cell blueprint, which comes from scanning a Tadpole fragment, and the Power Cell itself needs Strong Acid, so buds sit on the path to your first Tadpole. The wiki also lists a Processor recipe that uses 1 Sulfur and 1 Gold instead. The Strong Acid guide covers both recipes and every item that uses the acid.
The wiki lists two smaller uses. Each bud is the cost of planting a new cyst in a Growbed, so keep a spare or two for replanting. Buds also work as Bioreactor fuel at 1,200 power over 2 minutes, which is the lowest tier in the wiki's fuel table, so they are better spent on acid.
07
Safety in the Necrolei Hills
The Necrolei is listed as passive, and the wiki documents no damage from harvesting a cyst, even though the databank calls the buds a renewable but dangerous source of acid. According to the wiki, the Coral Gardens has the smallest population of aggressive lifeforms of any region, but two hazards in the hills are documented:
- Foureye: this fish is listed as defensive with 5 damage. It usually ignores you, but it dashes at you if you look it in the eye for too long.
- Acid Raion: found in the Necrolei Hills caves. It is listed as passive, but cut its three pouches off with the Survival Multitool before you pick its Medical Gel Sac, or it sprays acid that damages you.
Apart from the Foureye, every hills lifeform with a listed attitude is passive, from Halfmoons and Periscopic Clowncrabs to the huge Deepwing Brooders. If this is one of your first trips away from the Lifepod, the beginner guide covers oxygen, food and early tools.
08
Other resources in the Necrolei Hills
The wiki lists Copper, Quartz, Silver, Titanium and Deepwing Egg Clumps in the open biome, and Acidic Raion Pouches, Medical Gel Sacs, Copper, Silver and Titanium in the Necrolei Hills caves; the Biomes overview adds Water Slugs. The hills also sit next to the Heat Tolerance Angel Comb area, and the wiki places the Northern Bloom Node for that adaptation about 240 m north of the Lifepod, next to a wreck bordering the hills. For where these materials fit into early recipes, see the resources guide.